1. Field of the Invention
The subject invention relates to a fluid transfer assembly for transferring liquids, such as medicinal substances, through a number of different tubes.
2. Description of Related Art
Fluid transfer assemblies having T-shaped or Y-shaped connectors for interconnecting three or more flexible tubes are well known in a variety of industries, such as the medical industry and the automotive industry. A typical T-shaped connector is illustrated in U.S. Pat. No. 6,308,992. The '992 patent discloses a T-shaped connector having a series of barbs with the tubes fitting over portions of the connector and interengaging the barbs to retain the tubes onto the T-shaped connector. Although the T-shaped connector of the '992 patent is specifically designed for an automotive application, similar T-shaped connectors are used in the medical industry.
Tubing used in the medical industry is frequently formed of silicone. Silicone is a relatively inert material such that the tubes and connector do not significantly degrade, react with or leach components as the medicinal substances pass through the tubes and connector. Other materials, such as polyvinyl chloride (PVC), are typically not used for transfer assemblies in pharmaceutical manufacturing as these materials can leach into the medicinal substances which will pollute the substance and destroy the purpose of the transfer assembly.
One drawback to the prior art connectors and tubes discussed above relates to a gap or void that is created between the tubes and the connector once the tubes are mounted to the connector. This gap or void can potentially accumulate medicinal substances which can then taint the proper dosage of the substance or be a location for potential microbiological growth. In addition, there is a potential that the tubes could become detached from the connector, which obviously creates a serious issue for appropriately transferring the medicinal substances.
One solution contemplated by the prior art eliminates the use of a traditional connector. As shown in U.S. Pat. No. 6,290,265, the connector and interconnection with the tubes are simultaneously created during a molding process. In particular, the tubes are inserted into a mold along with a rigid member. Liquid silicone is then injected into the mold about the tubes and the member. The liquid silicone is cured to form the connector and interconnect the tubes. Although the process for forming the transfer assembly shown in the '265 patent may avoid some of the issues described above, this process is considerably complicated and requires a number of steps to create the transfer assembly. Another solution contemplated by the prior art is shown in U.S. Pat. No. 6,432,345. The '345 patent discloses a T-shaped connector disposed within a mold and spaced from a plurality of tubes. Rigid pins interconnect the apertures of the connector with apertures of the tubes. Liquid silicone is then injected into the mold and is cured about the tubes and pins to interconnect the tubes to the manifold. The prior art system contemplated by the '345 patent may also avoid the deficiencies outlined above, but similarly suffers from being overly complicated and having numerous process steps.
Accordingly, there remains a need for developing a transfer assembly which is simple and easy to manufacture, minimizes voids or gaps which can accumulate substances, and securely fastens the tubes to the connector.